Tamper for baler

ABSTRACT

A tamper for a baler, as for waste paper, which includes a plunger movable downwardly into an auxiliary compression space above the compression space for the baler forwardly of the platen. The feed chute extends to the top of a feeding space at one side of the auxiliary space, the feeding space having an inclined side, so that the baler may be operated either with or without the tamper. Controls for the tamper and baler include limit switches and maintain the plunger in down position until the baler platen has moved forwardly part way, to increase the shearing effect of the top edge of the platen and decrease the material shoved back up into the auxiliary compression space. A safety device for the tamper plunger includes a cable connected to a cross bar, the upper ends of which rest on compression springs at the top of the tamper, so that the maximum downward movement of the tamper plunger will be slightly above the upper edge of the path of movement of the baler platen. The safety device is particularly effective if the tamper plunger should be moved downwardly, as by manual control, when there is little or no paper in the auxiliary compression space.

United States Patent [191 Friedman et al.

1 TAMPER FOR BALER [75] Inventors: Hyman Friedman, Denver, Colo;

Melvin C. Michael, 8275 Eaton Way, Arvada, Colo. 80002 [73] Assignee: Said Friedman, by said Michael [22] Filed: May 17, 1971 [21] Appl. No.: 143,883

[52] US. Cl 100/49, 100/45, 100/50, 100/53,100/137,100/143,l00/180,

[51 I Int. Cl. B30b 7/04 158] Field of Search .L 100/42, 45, 49, 53, 100/187, 192, 50, 52, 53,180,137,138,139,

H 1 Oct. 2, 1973 Primary Examiner-Billy J. Wilhite Attorney-Van Valkenburgh and Lowe 57 ABSTRACT A tamper for a baler, as for waste paper, which includes a plunger movable downwardly into an auxiliary compression space above the compression space for the baler forwardly of the platen. The feed chute extends to the top of a feeding space atone side of the auxiliary space, the feeding space having an inclined side, so that the baler may be operated either with or without the tamper. Controls for the tamper and baler include limit switches and maintain the plunger in down position until the baler platen has moved forwardly part way, to increase the shearing effect of the top edge of the platen and decrease the material shoved back up into the auxiliary compression space. A safety device for the tamper plunger includes a cable connected to a cross bar, the upper ends of which rest on compression springs at the top of the tamper, so that the maximum downward movement of the tamper plunger will be slightly above the upper edge of the path of movement of the baler platen. The safety device is particularly effective if the tamper plunger should be moved downwardly, as by manual control, when there is little or no paper in the auxiliary compression space.

8 Claims, 7 Drawing Figures PATENIED 21915 3.762.311

SHEET 10F 3 [L INVENTORS HYMAN FRIEDMAN MELVIN C. MICHAEL ATTORNEYS PATENTED 2|975 sum 30F 3 IN VENTORS HYMAN FRIEDMAN MELVIN C. MICHAEL BY l aw [/M E ATTORNEYS 1 TAMPER FOR BALER This invention relates to balers, such as balers for compressing waste paper'and the like into bales, and particularly to a tamper for increasing the capacity of the baler.

In the conventional baler utilized for compressing waste paper and the like into bales, a feed chute delivers the paper supplied, as from a conveyor, to a pipe through which the paper is blown by a blower or the like, with the paper falling into a compression space. A ram operated platen moves, normally horizontally, through the compression space to compress the paper against a previously formed bale, or against a block which separates the bales. A series of dogs distributed around the end of the compression space holds the compressed paper until another supply of paper can be fed into the compression space, then compressed by the platen. The ram or hydraulic cylinder for the platen may be operated by a hydraulic fluid at two different pressures, such as a lower pressure for a predetermined proportion of the length of movement of the platen, and a higher pressure thereafter, for the final compression. This is advantageous, since a low pressure, high volume pump can be utilized to move-the 'platen through most of this movement, with a high pressure, low volume pump utilized to supply the hydraulic fluid for the final movement of the platen.

In some instances, particularly when the paper is in a relatively light and fluffy condition, as when blown through a supply-pipe by a blower, the amount of paper which will be deposited by gravity in the compression space, when finally compressed, will occupy a much smaller portion of the total length of the bale, for each strokeof the platen. Thus, it may be necessary to operate the platen for up to twice its usual number of strokes, in order to produce a compressed bale of the desired length. This limitation upon the capacity of the baler has an adverse effect upon the production rate of the equipment which supplies the paper to the baler, since it often must be slowed down to accommodate the decreased capacity of the baler.

After a predetermined length of paper has beencompressed in the baler, i.e., the desired length of a bale, a series of wires is tied around each bale, to retain the bale in compressed condition, after discharge from the which follows, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an isometric view of a baler equipped with a tamper and feed chute constructed in accordance with the present invention;

FIG. 2 is a vertical, longitudinal section, taken centrally of the tamper and just within the near side of the baler and showing approximately the rear half of the machine;

FIG. 3 is a fragmentary side elevation, on an enlarged scale, of the portion of the baler occupied by a baler platen and showing particularly control components which are omitted in FIG. 1 for clarity of illustration;

FIG. 4 is a side elevationof the tamper;

FIG. 5 is a transverse vertical section of the tamper, baler and feed chute, taken along line 5-5 of FIG. 2;

FIG. 6 is a horizontal section of the tamper taken along line 6-6 of FIG. 5, but on a slightly enlarged scale; and

FIG. 7 is a control circuit diagram for the tamper.

As illustrated in FIGS. 1 and 2, the baler comprises essentially a lo ngitudinally extending framework F which includes, rearwardly of 'thecenter thereof, a compression space S of FIG. 2 through which a baler platen B is adapted to move. A series of conventional spring pressed dogs 9 operate to catch each increment of the compressed paper, as it is moved toward the preceding bale or conventional block separating the preceding bale from the bale being formed. Ordinarily, the feed chute would be disposed vertically above the compression space in the position of the tamper T, with the paper falling into'the compression space from above. With such a conventional feed chute, a pair of control devices, such as a source of light directed across the feed chute and a photocell on the opposite side, are utilized, with a lower light and photocell being mounted on the feed chute above the compression space a distance slightly greater than the height of the compression space, and an upper light source and photocell being mounted on opposite sides of the feed chute an equivalent distance above the lower light source and photocell. The lower light source and photocell are utimachine. Normally, several bales are present in the discharge portion of the baler, with the sides and top of the discharge. chuteproducing compression against the bales, particularly at the discharge end, so as to resist the impact of the platen against the paper in the compression space and retain the paper in compressed condition until the bale can be secured, as by wires.

. Among the objects of the present invention are to provide a novel tamper particularly adapted to increase the capacity of a baler; to provide a novel cooperation between the tamper and the feed chute by which paper or the like is supplied to the baler; to provide a novel cooperation between the platen and the tamper, to minimize the tendency of the paper to curl upwardly from the compression space as the platen moves therethrough; and to provide such a tamper which, in cooperation with the baler, will be relatively simple yet rugged in construction and efficient and effective in operation.

Additional objects and the novel features of this invention will become apparent from the description lized to control the movement of the platen, in order to prevent platen movement until thepaper falling into the feed chute and thence into the compression space reaches that height, while the upper light source and photocell are used to control the equipment supplying paper to the feed chute, so that if the paper collects in the feed chute to the height of the upper control, the supply equipment can be stopped until the baler .can clear away the paper available for compression. Each light source and photocell is adjusted so as to be responsive to paper stopped in the feed chute at the position thereof, rather than merely paper falling past such position.

Just prior to discharge, each bale l0 provided'with clamping wires 11 reaches a discharge end tensioning device D of the baler, which exerts thedesired pressure against each bale, in turn, in order to provide a solid backing at the discharge end of the compression space.

S of FIG. 2. The end tensioning device D is'described in greater detail later, but may be of any conventional construction. As indicated previously, a fresh supply of paper in the compression space may be compressed by the platen B against the end of the previously compressed bale, or a conventional block separating the previously compressedbale from the new bale, or the previously compressed portions of the bale being formed, as held by the dogs 9 in a conventional manner. The platen B may be conventional in construction, including a front plate 12 connected to a pair of upright side beams 13 and a lower, transverse beam 14, with beams 13 conveniently being formed of hard wood, so as to move along side plates 15 and 16 of frame F, which extend forwardly and rearwardly of compression space S, and, while so moving, scrape paper away from the wall plates. Lower beam 14 of the platen is also conveniently formed of hard wood, so as to move along a bottom plate 17, which extends from beneath the platen to the opposite end of the machine. Front plate 12 may be connected to beams 13 and 14 by reinforcing metal angles or channels which also provide a connection point for a piston rod 18 extending from an hy-- draulic cylinder 19, the opposite end of which is attached to transverse bar 20 at the rear end of the framework F, as shown. The lower end of the platen may be provided with a pair of rollers 21 adapted to move along the elongated, horizontal bottom plate 17, which extends beneath the compression space and also supports the bales for movement until discharge. The platen is also providedwith a top cover plate 22 which is mounted on a pair of longitudinal beams 23, with one at each side and each carrying, at its rear end, a roller 24 which is adapted to move along a guide angle 25. The platen may be reinforced by a diagonal strut 26, on each side, extending from the rear end of a respective longitudinal beam 23 to the lower end of the front of the platen. A wood spacing block 27 extends across the top of the rear edge of the compression space, as in FIG. 2, with the cover plate 22 for the platen moving underneath the spacing block along the dotted line 28 and the front edge of front plate 12 of the platen being movable past the dogs 9, as to the upright dotted line 29. Additional details of the baler construction, which is essentially a conventional one, will be given later.

For semi-automatic operation of the baler platen, without the tamper T, a pair of limit switch actuating bars 30 and 31, as in FIG. 3, may extend transversely from one of the struts 26, while a limit switch actuating bar 32 may be mounted on the strut to extend longitudinally and an actuating bar 33 mounted to extend rearwardly from the front of the platen. A stationary framework 34 may support a limit switch 35 for actuation by bar 33, a limit switch 36 for actuation by bar 30, a limit switch 37 for actuation by bar 31 and a limit switch 38 for actuation by bar 32. Also, a limit switch 39 may be positioned for actuation by a bar 40, extending rearwardly from the front of the platen, for use in control of the tamper T, in a manner described later. In general, when the electric eye described previously is occluded by paper at a sufficient height above the compression space, the platen will start forward by hydraulic pressure furnished at low pressure and high volume, until the pressure of the fluid supplied to the cylinder increases to approximately the maximum value produced by the low pressure pump, whereupon the supply of hydraulic fluid will be changed to low volume at high pressure. When bar 30 trips limit switch 36, the platen will be stopped, in a position corresponding to dotted line 29 of FIG. 2. When limit switch 36 is triggered, the platen will be automatically returned, with bar 32 and limit switch 38 controlling a cushioning effect near the end of the return stroke and limit switch 35 is actuated at the end of the return stroke, which is necessary for the tamper to start another forward stroke. Limit switch 37 controls the operation of a block dropper, which is referred to later generally, but the operation of which is not significant to the present invention.

In accordance with the present invention, the tamper T is mounted directly above the compression space S, as in FIGS. 1 and 2, and includes a movable plunger P which operates within the stationary portion of the tamper. The latter includes, as in FIG. 5, a vertical side wall 42 which extends upwardly from one side of the compression space, with the opposite side wall having a portion 43 which extends upwardly for a short distance, then a portion 44 which inclines angularly outwardly, as at approximately 45 to the horizontal, then a portion 45 which extends upwardly to the lower edge of the feed chute C. The end walls 46 of the tamper have a configuration corresponding to the space between the side walls shown. The walls 42, 44, 45, 46 enclose an auxiliary compression space S of FIG. 5 below the tamper P and a feeding space laterally therefrom, with the feeding space having nearly or approximately the volume of the auxiliary compression space. The movable portion or plunger-P of the tamper includes a rectangular lower plate 47 reinforced around its edges by angles 48 and mounted at the lower end ofv four upright slide angles 49 which move within a series of stationary, upright, guide angles 50, as in FIG. 6. The tops of slide angles 49 are connected by a rectangular structure formed by angles 51, while the guide angles 50 are similarly connected at the top by angles 52 of FIGS. 1

and 2. The lower plate 47 and upper angles 51 are reinforced by crossing diagonal bars 53, while a pair of end plates 54 at each end and a pair of side plates 55 extend between the respective upright angles 49, inorder to form, with the bottom plate 47, a plunger. which is closed at the bottom and also on all four sides. The plates 54, at each end, are spaced apart at the center by a channel 56, in which is installed a rack 57, with each rack adapted to engage a gear 58 for raising and lowering the plunger in normal operation.

Each gear 58, as in FIGS. 2, '3 and 6, is mounted on a shaft 60 journaled in bearings 61 mounted on the outside of stationary guide angles 50 and provided with a drive sprocket 62 on the outboard end. A housing 63 encloses each rack gear 58, while the outboard sprockets 62 of each shaft engage opposite sides of a chain 64 which, as in FIG. 4, is driven by a reversible hydraulic motor 65 through a sprocket 66. A tension or idler sprocket 67 is adjustably mounted on a cross bar 68 which is mounted on the outside of two of the stationary guide angles 50. Hydraulic motor 65 is mounted on a platform 69, so that upon rotation in one direction, such as indicated by the arrow 70 of FIG. 4, the gears 58 will rotate in a direction to move the plunger downwardly. Upon rotation of the hydraulic motor in a direction opposite to the arrow 70, the gears 58 will rotate to lift the plunger.

The rectangular structure provided by angles 52 supports, at two corners, a pair of upright tubes 71 which are provided with a longitudinal slot 72 therein, as in FIGS. 1, 2 and 5, to accommodate movement of a cross beam 73 against a pair of compression springs 74 mounted in the tubes 71. One end of a safety cable 75 is attached to the center of upper diagonal brackes 53, with the opposite end being attached to the underside of cross beam 73.

The feed chute C is rectangular in cross section, having end walls 76 and side walls 77, 77' which slant downwardly to and are attached to the upper edges of side wall portion 45 and end walls 46, laterally from the position of plunger P. Side wall 77' of the feed chute is attached to the lower edge of an upright plate 78, which extends between angles 50 adjacent the feed chute, to prevent paper from being pulled back by the plunger as it is lifted. Feed chute C may also be provided with a pair of electric eyes, i.e. a photoelectric cell 79 or 80 mounted in one end wall 77, as in FIG. 5, and a light source 79' or 80' mounted in the other end wall opposite the photocell, as in FIG. 1. Photocell 79 prevents the plunger P from descending unless the paper is up to the height thereof, while photocell 80 stops the supply of paper to the feed chute, if the paper backs up in the feed chute to that level. An access door 81, as in FIG. 1, is provided in one end wall 46, just below the feed chute, to permit cleaning away of a paper jam, as well as inspection.

During normal operation of the tamper, the plunger P will move downwardly to a position corresponding to the amount of paper or the like which may be compressed by the tamper in the compression space S and also in the auxiliary compression space S directly thereabove. Thus, the racks 57 move downwardly along the upright dotted lines 82 of FIG. 2, but the lower plate 47 of the plunger can move downwardly only to the horizontal dotted line 83, so as to be spaced above the cover plate 22 of the platen, as it moves across the compression space. The line 83, which indicates the limit of the downward movement of the platen and corresponds to the top of spacing block 27, is determined by the drop of the platen without any paper in the compression space, when the safety cable 75 receives the full weight of the platen and pulls the cross beam 73 downwardly against the compression springs 74. The safety cable 75 is thus a valuable feature of this invention, since it prevents the tamper from moving into the compression space S, particularly if the tamper should accidentally be dropped, and there is insufficient paper collected below the tamper plunger to stop the plunger above the line 83.

The extent of the upward and downward movement of the platen may also be controlled by limit switches, such asan upper limit switch 85 mounted near the upper end of an angle 50, as in FIGS. 1 and 4, and adapted to be actuated by a bar 86 mounted in an appropriate position on a side wall plate 54 of the plunger P, as in FIG. 1, to actuate the limit switch 85 when the plunger returns to its upper position. A lower limit switch 87 may be mounted on the same angle 50, so as to be actuated by bar 86 when the plunger P moves to a desired lower position, such as one-half to one inch above the dotted line 83 of FIG. 2, which indicates the maximum downward movement of the plunger when arrested by the safety cable 75, as described previously. As will be evident, the length of plunger P is greater than its total permitted movement, in order to insure guidance of the plunger by angles 50 at the start of upward movement. Thus, the lower limit switch 87 is mounted a corresponding distance above the lower edge of the plunger, when in its raised position.

While the tamper plunger P may be operated through manual or automatic control, as described below, one of the advantages of the present construction is that the tamper plunger may be left in the upper position of FIGS. 2 and 5 and the baler operated in the usual manner, without the tamper, as when the material to be baled, such as heavy cardboard, does not required precompression for the baler to achieve its desired capacity. As will be evident from FIG. 5, the paper can fall directly from the chute C into the compression space S, being guided by the inclined portion 45 of the side wall of the tamper housing beneath the chute, i.e., through a feeding space above wall portion 44, into the auxiliary compression space S and thence into the platen compression space S. Only a slight variation in the control is necessary for this purpose. Thus, when light or fluffy material is to be baled, the tamper may be utilized; when heavy, dense material is to be baled, the the baler may be used without the tamper. As will be evident, this would not be true if the tamper operated horizontally, for instance, to compress material into the platen compression space.

For controlling the operation of the tamper in conjunction with the platen, the circuit of FIG. 7 includes leads 88 and 88 by which current may be supplied to the controls of an appropriate voltage, with a branch lead 89 leading to a selector switch 90 adapted to be shifted in either automatic or hand operation positions. Other elements of the circuit include an up switch 91 and a down switch 92, for manually controlling the respective movements of the platen; the solenoid or coil 93 of an up relay and the solenoid or coil 94 of a down relay; a solenoid control 95 for the up valve, i.e., the valve which supplies hydraulic fluid to the hydraulic motor 65, in order to turn the motor in a direction to move the tamper plunger P upwardly; a solenoid 96 for operating the down valve, i.e., the valve which supplies hydraulic fluid to the reversible motor 65, in order to cause the motor to turn in a direction to cause the platen plunger P to move downwardly. The circuit also includes a pressure switch 97 which is responsive to the pressure of fluid supplied to the reversible hydraulic motor 65, particularly through the down valve, so that, if the plunger P should encounter sufficient resistance during its downward stroke before it reaches the position at which the lower limit switch 87 would be tripped, the plunger will be automatically stopped. Also included in the circuit is a down relay terminating contact 98 which is normally open, but which, when the pressure switch 97 closes, will deactivate the down relay.

In the circuit of FIG. 7, when the selector switch 90 is moved to the contact 90a, automatic operation willv ensue, but when moved to the contact 90h, the plunger may be operated by hand. Thus, the up switch 91 and the down switch 92 are in parallel from the contact 90h. The down manual switch 92 is connected in series with the down relay 94 which, when energized, will close a normally open down relay contact 940, in series with the down valve solenoid 96, to start the plunger downwardly. A normally closed contact 93c of the up relay and a normally closed contact 87c of the lower limit switch 87 are also in series with the contact 940 and the down valve solenoid 96, to insure that the up relay is not energized and the down limit switch is clear, before the down valve can be opened. For manual operation, when the up manual switch 91 is closed, the up relay solenoid 93 is energized, provided that a normally closed contact c of the upper limit switch 85.is closed and a normally closed contact 940 of the down relayv is also closed, the latter two parts being in series between the up manual switch 91 and the up relay solenoid 93. When the up relay solenoid 93 is energized, a normally open holding contact 93): is closed, as well as a normally open contact 930 in series with the up vale solenoid 95. Of course, the plunger can be stopped at any desired point by releasing the up manual switch 91 or the down manual switch 92, depending upon the direction the plunger is travelling.

For automatic operation with the selector switch 90 moved to contact 90a, a connection is provided through the contacts 85c and 940 to up relay solenoid 93, as well as to the down relay solenoid 94 through a normally open photocell control contact 790 and the normally closed contact 39c of platen limit switch 39, i.e. both the photocell 79 must be occluded and the bar 40 in engagement with the limit switch 39 of FIG. 2, before the platen will move downwardly. A normally open contact 850 of the upper limit switch 85 is placed in series between the photocell control contact 7 90 and the down relay solenoid 94. As. soon as the latter is energized, a normally open holding contact 94h will be energized to maintain the solenoid 94 energized until the contact 39c of limit switch 39 opens, indicating that the platen has travelled a predetermined distance, such as percent of its total travel across the compression 7 space. As will be evident, when the normally closed up limit switch contact 850 is opened, the up relay solenoid 93 will be deenergized. At the same time, the normally open contact 850 of the upper limit switch will be closed, permitting the down relay solenoid 94 to be energized, provided that the photocell control normally opened contact 790 is closed, and also the normally closed contact 39c of limit switch 39 is closed. The operation of thetamper is, of course, correlated with the operationof the baler platen, although the operation of the latter is essentially conventional, except that during automatic operation, the baler platen cannot move forward until the tamper has moved toits down position. Nevertheless, when it is desired to operate the baler platen without the tamper, as described previously, it is a very simple matter to shift the control of the forward movement of the baler platen from the down position of the tamper plunger to a contact controlled by photocell 79.

In general, the automaticoperation of the tamper and baler, when the baler plunger has completed a return movement, is thus the downward movement of the tamper, when the photocell 79 indicates a sufficient supply of paper, with the tamper plunger moving downwardly until the lower limit switch 87 is tripped or the pressure switch 97 stops the plunger, as a result of the plunger reaching its capacity for compression. The baler platen then starts forwardly and the tamper plunger does not start upwardly until the limit switch 39 is tripped. In effect, the tamper plunger waits for the baler platen to start on its movement. This is of assistance in increasing the capacity of the baler, since the upper edge of the platen moving through the material, precompressed by the tamper, will start shearing through the material as long as the tamper remains in its down position. This shearing action tends to proceed through the precompressed material in-the same plane thus started, which plane corresponds to the top surface of the baler cover plate 22 of FIG. 2. However, if the tamper plunger is moved upwardly before the baler platen starts its compression stroke, the precompressed material would tend to curl upwardly into the tamper space S, with the result that less material would be compressed by the baler platen than it has the capacity to do so.

As the tamper plunger starts upwardly, the baler platen continues forwardly until the limit of its movement is reached, as by tripping limit switch 36. While the baler platen is completing its forward movement, the tamper plunger is, of course, moving upwardly and will reach its top position at somewhere near the same time that the baler platen completes its forward stroke. This permits paper to fall onto the top of the baler platen cover plate and thence into the baler compression space S as the platen moves rearwardly, as well as fill the space 8' below the platen plunger and the feeding space laterally thereof. Thus, shortly after the baler platen has returned, there should be sufficient paper in the baler compression space S and the tamper compression space S, as well as paper extending up to the feed chute, to cover the photocell 79, so that the tamper plunger can start on its next stroke.

When a bale has been completed, as to a predetermined length, such as through a conventional measuring wheel and signalling device, the baler platen is stopped a short distance from the beginning of its return stroke, as by limit switch 37, so that a block may be dropped or a special wire inserting device utilized to pass the wires behind the bale just formed. The baler platen may be forced against the block or against the inserted wires, while thewires are being tied. Since the baler plunger may require some 15 to 20 strokes to form a bale, the time required for wire tying, such as one minute, does notunduly detract from the capacity of the baler. 7

Conventional switches for manual operation of the baler platen and also for shifting the operation of the baler platen to automatic control, as well as the switches which operate the tamper, such as the selector switch and manual switches 91 and 92, may be mounted on a panel placed in a readily accessible position, such as shown in FIG. 1. The remainder of the baler may be conventional, as indicated previously. Thus, the discharge end tensioning device D may include, to engage the bales just prior to discharge, a series of side shoes on opposite sides thereof, and also the downwardly pressed free end of a top plate 106, which is urged downwardly by an hydraulic cylinder 107 operating between the top plate and the upper end of an inverted U-shaped stanchion 108. The pressure of side shoes 105 may also be adjusted from an upright bar 109 on which the side shoes are mounted. Tension rods 110 hold the stanchion 108 against the pressure of the bales. The bottom plate 17 may be supported by longitudinal beams 111 and transversebeams 112, being reinforced beyond the compression space by side plates 113, with depending plates 114 reinforcing the top plate 106. An hydraulic fluid tank 115 is mounted directly above the platen cylinder and supports conventional motors, pumps and hydraulic and electrical devices, as shown, for the movement of the platen. Conventional hydraulic hoses or piping (not shown) connect the various pumps with the hydraulic cylinder 19 and the latter with the hydraulic fluid tank 115. A block dropper 1l6 may be mounted on the frame F just forwardly of the tamper T,- although the wires may be tied on each bale as completed, thereby eliminating the blocks. Controls 117 for the block dropper and the discharge tensioning device may be mounted on the frame forwardly of the block dropper. The control planel 100 may be mounted on the frame just forwardly of the block dropper, while an electrical circuit box 118 and a switch box 119 may be mounted on the outside of the compression space in a conventional manner.

Although a preferred embodiment of this invention has been illustrated and described, it will be understood that other embodiments may exist and that various changes may be made therein, without departing from the spirit and scope of this invention.

What is claimed is:

1. In a baler for paper and thelike having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means'for resisting movement of previously compressed increments .beyond said holding means, the improvement comprising:

means providing an auxiliary compression space above said platen compression space;

tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly; means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said, platen compression space may be pre-compressed into said platen compression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen; said plunger including a rectangular lower plate, up-

right corner slide members, a series of members in rectangular relation connecting the upper ends of said corner members, a side plate forming a closure for each side of said plunger, a pair of end plates and a channel between each pair of end plates forming a closure for the ends of said plunger, and a rack mounted in each said channehand said tamper including a series of four stationary, upright guide members mounted for slidable engagement with said corner member of said plunger, a gear in engagement with each rack and disposed adjacent the lower end of said plunger whensaid plunger is in its upper position, and reversible drive means for turning said gears in opposite directions, so as to move said plunger downwardly and upwardly.

2. In a baler for paper and the like, as defined in claim 1, including:

at least one reinforcing member extending acrossthe upper end of said plunger, a pair of tubes mounted on and extending upwardly from the upper end of diagonally opposed guide members of said tamper, each said tube having a longitudinal slot'therein facing the opposite tube;

a compression spring disposed within each said tube;

a cross bar extending between said tubes and through said slots to engage the upper end of each of said springs; and

a cable having one end attached to said cross bar and the opposite end attached to said reinforcing member at the upper end of said plunger for terminating downward movement of said plunger at a predetermined position.

3. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of the previously compressed increments beyond said holding means, the improvement comprising:

means providing an auxiliary compression space above said platen compression space;

tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly;

means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said platen compression space may be pre-compressed into said platen-compression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen;

said platen being provided with a top cover plate and said tamper plunger being moved upwardly and downwardly by a reversible hydraulic motor; and

control means for said tamper plunger comprising:

a solenoid controlled up valve for causing hydraulic fluid to be supplied to said motor for movement of said plunger upwardly;

a solenoid controlled down valve for causing hydraulic fluid to be supplied to said 'motor for moving said plunger downwardly;

an up relay having a normally open contact in series with said up valve solenoid;

a down relay having a normally open contact in series with said down valve solenoid;

an upper limit switch responsive to the upper position of said tamper plunger and having a normally closed contact in series with said up relay;

lower limit switch actuated when said plunger reaches a lower position and having a normally open contact, also in' series with said up relay,,and a normally closed contact in series with said down valve solenoid, said up relay also having a normally closed contact in series with said down valvesolenoid; said down relay having a normally closed contact in series between said upper limit switch contact and said up relay; amanually actuable down switch in series withsaid down relay;

a manually actuable up switch in series with said upper limit switch normally closed contact, said normally closed down relay contact and said up rey;

means responsive to the height of paper and the like in said feed space and controlling a normally open contact in series with said down relay;

a limit switch operated by said platen and having a normally closed contact which remains closed until said platen reaches a predetermined portion of its movement across said compression space, said platen limit switch contact being in series with said photoelectric controlled contact and said down relay; a normally open pressure switch which is closed by pressure of hydraulic fluid supplied to said motor reaching a predetermined amount of pressure during downward movement of said plunger, said pressure switch being in series with said up relay; and a normally open down relay contact which is closed when said down relay is deenergized and which is in series with said pressure switch and said up relay. 4. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of previously compressed increments beyond said holding means, the improvement comprising:

means providing an auxiliary compression space above said platen compression space;

tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly;

means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said platen compression space may be pre-compressed into said platen com pression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen; and

resilient safety device for arresting downward movement of said plunger, with the lower end of said plunger being slightly above the position of the top of said baler platen, when so arrested.

5. In a baler for paper and the like, as defined in claim 4, wherein said safety device includes:

a cable having one end attached to said plunger; and

a member, to which the opposite end of said cable is attached, associated with resilient means constructed and arranged to resist downward movement of said plunger when said cable is tightened between said plunger and said member, for arrest-.

ing downward movement of said plunger, with the lower end of said plunger being slightly above the position of the top of said baler platen, when so arrested.

6. in a baler for paperand the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of previously compressed increments beyond said holding means, the improvement comprising: means providing an auxiliary compression space above said platen compression space and a feeding space laterally of said auxiliary compression space; tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly, said feeding space extending downwardly substantially to said platen compression space and upwardly to the upper end of said auxiliary compression space, with the lower portion of said feeding space converging downwardly; means responsive to the level of material in said feeding space adjacent the upper end thereof; means controlled by said level responsive means for retaining said plunger in an upper position until-the level of material in said feeding space has reached said level responsive means; and a feed chute extending downwardly to the upper end of said feeding space, for supplying material to said feeding space, said auxiliary compression space and said platen compression space, the construction and arrangement, being such that material moving from said feed chute through said feeding space into said auxiliary compression space and said platen compression space may be precompressed into aid platen compression space by said tamper plunger, unless said plunger is retained in its upper position, for compression in said platen compression space by said platen. i 7. in a baler for paper and the like, as defined in claim 6, including:

means for moving said platen forwardly for com pressing material, in said compression space, which has previously been pre-compressed by said plunger, said platen having an upper plate; and means for retaining said plunger in its lower position for a predetermined portion of the forward movement of said platen and for causing said plunger to then move upwardly, whereby said plunger will have reached its upper position near the same time at which said platen reaches the end of its forward stroke and material can fall from said feeding space on top of said platen and then into said platen compression space as said platen moves rearwardly. 8. In a baler for paper and the like, as defined in claim 6, wherein: I

said feeding space has approximately the volume of said auxiliary compression space.

l 10! l I 

1. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of previously compressed increments beyond said holding means, the improvement comprising: means providing an auxiliary compression space above said platen compression space; tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly; means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said platen compression space may be pre-compressed into said platen compression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen; said plunger including a rectangular lower plate, upright corner slide members, a series of members in rectangular relation connecting the upper ends of said corner members, a side plate forming a closure for each side of said plunger, a pair of end plates and a channel between each pair of end plates forming a closure for the ends of said plunger, and a rack mounted in each said channel; and said tamper including a series of four stationary, upright guide members mounted for slidable engagement with said corner member of said plunger, a gear in engagement with each rack and disposed adjacent the lower end of said plunger when said plunger is in its upper position, and reversible drive means for turning said gears in opposite directions, so as to move said plunger downwardly and upwardly.
 2. In a baler for paper and the like, as defined in claim 1, including: at least one reinforcing member extending across the upper end of said plunger, a pair of tubes mounted on and extending upwardly from the upper end of diagonally opposed guide members of said tamper, each said tube having a longitudinal slot therein facing the opposite tube; a compression spring disposed within each said tube; a cross bar extending between said tubes and through said slots to engage the upper end of each of said springs; and a cable having one end attached to said cross bar and the opposite end attached to said reinforcing member at the upper end of said plunger for terminating downward movement of said plunger at a predetermined position.
 3. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of the previously compressed increments beyond said holding means, the improvement comprising: means providing an auxiliary compression space above said platen compression space; tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly; means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said platen compression space may be pre-compressed into said platen compression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen; said platen being provided with a top cover plate and said tamper plunger being moved upwardly and downwardly by a reversible hydraulic motor; and control means for said tamper plunger comprising: a solenoid controlled up valve for causing hydraulic fluid to be supplied to said motor for movement of said plunger upwardly; a solenoid controlled down valve for causing hydraulic fluid to be supplied to said motor for moving said plunger downwardly; an up relay having a normally open contact in series with said up valve solenoid; a down relay having a normally open contact in series with said down valve solenoid; an upper limit switch responsive to the upper position of said tamper plunger and having a normally closed contact in series with said up relay; a lower limit switch actuated when said plunger reaches a lower position and having a normally open contact, also in series with said up relay, and a normally closed contact in series with said down valve solenoid, said up relay also having a normally closed contact in serieS with said down valve solenoid; said down relay having a normally closed contact in series between said upper limit switch contact and said up relay; a manually actuable down switch in series with said down relay; a manually actuable up switch in series with said upper limit switch normally closed contact, said normally closed down relay contact and said up relay; means responsive to the height of paper and the like in said feed space and controlling a normally open contact in series with said down relay; a limit switch operated by said platen and having a normally closed contact which remains closed until said platen reaches a predetermined portion of its movement across said compression space, said platen limit switch contact being in series with said photoelectric controlled contact and said down relay; a normally open pressure switch which is closed by pressure of hydraulic fluid supplied to said motor reaching a predetermined amount of pressure during downward movement of said plunger, said pressure switch being in series with said up relay; and a normally open down relay contact which is closed when said down relay is deenergized and which is in series with said pressure switch and said up relay.
 4. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of previously compressed increments beyond said holding means, the improvement comprising: means providing an auxiliary compression space above said platen compression space; tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly; means for supplying material to said auxiliary compression space, the construction and arrangement being such that material moving into said auxiliary compression space and said platen compression space may be pre-compressed into said platen compression space by said tamper plunger, for compression in said platen compression space by said platen, and said plunger may be retained in an upper position so that material may move into said platen compression space for compression by said platen; and a resilient safety device for arresting downward movement of said plunger, with the lower end of said plunger being slightly above the position of the top of said baler platen, when so arrested.
 5. In a baler for paper and the like, as defined in claim 4, wherein said safety device includes: a cable having one end attached to said plunger; and a member, to which the opposite end of said cable is attached, associated with resilient means constructed and arranged to resist downward movement of said plunger when said cable is tightened between said plunger and said member, for arresting downward movement of said plunger, with the lower end of said plunger being slightly above the position of the top of said baler platen, when so arrested.
 6. In a baler for paper and the like having a platen movable across a compression space for engaging material movable into said space from above said space, to compress said material in increments against the material previously compressed, said baler having means for holding compressed increments in position upon return movement of said platen and means for resisting movement of previously compressed increments beyond said holding means, the improvement comprising: means providing an auxiliary compression space above said platen compression space and a feeding space laterally of said auxiliary compression space; tamper means having a plunger mounted for reciprocatory movement downwardly in said auxiliary compression space and then upwardly, said feeding space extending downwardly substantially to said plaTen compression space and upwardly to the upper end of said auxiliary compression space, with the lower portion of said feeding space converging downwardly; means responsive to the level of material in said feeding space adjacent the upper end thereof; means controlled by said level responsive means for retaining said plunger in an upper position until the level of material in said feeding space has reached said level responsive means; and a feed chute extending downwardly to the upper end of said feeding space, for supplying material to said feeding space, said auxiliary compression space and said platen compression space, the construction and arrangement being such that material moving from said feed chute through said feeding space into said auxiliary compression space and said platen compression space may be pre-compressed into aid platen compression space by said tamper plunger, unless said plunger is retained in its upper position, for compression in said platen compression space by said platen.
 7. In a baler for paper and the like, as defined in claim 6, including: means for moving said platen forwardly for compressing material, in said compression space, which has previously been pre-compressed by said plunger, said platen having an upper plate; and means for retaining said plunger in its lower position for a predetermined portion of the forward movement of said platen and for causing said plunger to then move upwardly, whereby said plunger will have reached its upper position near the same time at which said platen reaches the end of its forward stroke and material can fall from said feeding space on top of said platen and then into said platen compression space as said platen moves rearwardly.
 8. In a baler for paper and the like, as defined in claim 6, wherein: said feeding space has approximately the volume of said auxiliary compression space. 